1. Field of the Invention
The present invention generally relates to the preparation of molecular or ionic supramolecular assemblies having a substantially enclosed volume and a framework structure that mimics a Platonic or Archimedean solid.
2. Related Art
Spontaneous self-assembly processes that lead to discrete spherical arrays are common in Nature. Indeed, spherical viruses (Caspar et al., D. & Klug, A. Physical principles in the construction of regular viruses. Cold Spring Harb. Symp. Quant. Biol. 27, 1–24 (1962)) (e.g. hepatitis B) and fullerenes (Kroto et al., H. W., Heath, J. R., O'Brien, S. C., Curl, R. F., Smalley, R. E. C60: Buckminster-fullerene. Nature 318, 162–163 (1985)) (e.g. C60) are well known examples in which noncovalent and covalent forces, respectively, direct the assembly of smaller sub-units (or synthons) into larger superstructures. A common feature of these shell-like architectures is their ability to encapsulate neutral and/or charged guests whose size, shape, and chemical exteriors complement their inner surfaces. (Casjens, S. Nucleic acid packaging by viruses, in Virus Structure and Assembly (ed. Casjens, S.) 75–147, Jones and Bartlett, Boston, 1995; Schwarz et al., H., Weiske, T., Bohme, D. K., Hrusdak, J. Exo- and endohedral fullerene complexes in the gas phase, in Buckminsterfullerenes, eds. Billups, W. E. & Ciufolini, M. A., 257–283, VCH, New York, 1993, the disclosures of which are incorporated by reference). Their interiors can often be regarded as unique phases of matter (Sherman et al., J. C. & Cram, D. J. Carcerand interiors provide a new phase of matter. J. Am. Chem. Soc. 111, 4527–4528 (1989)) capable of controlling the flow of reactants, transients, and products and catalyzing reactions of both chemical and biological relevance. Such properties have inspired the recent emergence of mono- and supramolecular dimeric molecular capsules (Sherman et al.; Garel et al., L, Dutasta, J.-P., Collet, A. Complexation of methane and chlorofluorocarbons by cryp-tophane-A in organic solution. Angew. Chem. Int. Ed Engl. 32, 1169–1171 (1993); Timmerman et al., P., Verboom, W., van Veggel, F. C., van Duynhoven, J. P., Reinhoudt, D. N. A novel type of stereoisomerism in calix[4]arene-based carceplexes. Angew. Chem. Int. Ed Engl. 33, 2345–2348 (1994); (Kang et al., J. & Rebek, J. Jr. Acceleration of a Diels-Alder reaction by a self-assembled molecular capsule. Nature 385, 50–52 (1997); Shimizu et al., K. D., Rebek, J. Jr. Synthesis and assembly of self-complementary calix[4]arenes. Proc. Natl. Acad. Sci. USA. 92, 12403–12407 (1995); the disclosures of which are incorporated by reference), many of which have been based upon the head-to-head alignment of bowl-shaped polyaromatic macrocycles such as calix[4]arenes. Despite the synthesis of these pseudo-spherical capsules, however, structural mimicry of frameworks akin to viruses and fullerenes, which are based upon the self-assembly of n>3 sub-units where surface curvature is supplied by edge sharing of regular polygons and/or polygons that exhibit quasi-equivalence, has remained elusive and promises to bear relevance in a number of areas including biology, chemistry, and materials science